Brian Harold Mason Papers, 1920s-1992

National Museum of Natural History (U.S.) Department of Mineral Sciences

Physical description:

1.5 cu. ft. (1 record storage box) (1 document box)

Type:

Manuscripts

Collection descriptions

Field notes

Date:

1920

1920-1992

1920s-1992

Summary:

These are the papers of Brian Harold Mason (1917-2009), Curator, Meteorites Division, Department of Mineral Sciences, National Museum of Natural History. Mason's research focused on the mineralogy and petrology of meteorites and cosmochemistry. Materials include correspondence, autobiographical information, field notebooks, research files and materials related to this biographical research on Victor Moritz Goldschmidt.

National Museum of Natural History (U.S.) Department of Mineral Sciences

Physical description:

1 cu. ft. (1 record storage box)

Type:

Manuscripts

Collection descriptions

Color photographs

Black-and-white photographs

Place:

Antarctica

Date:

1953

1953-2001

Summary:

These are the papers of Brian Harold Mason, Curator Emeritus, Meteorites Division, Department of Mineral Sciences, National Museum of Natural History. Mason curates and classifies the 700+ meteorites recovered each year from Antarctica under a joint Smithsonian-National Aeronautics and Space Administration (NASA)-National Science Foundation program. His research focuses on the mineralogy and petrology of meteorites and cosmochemistry. Materials include correspondence, memoranda, and project files pertaining to the Allende Meteorite, Antarctic meteorites, and a biography of Victor Moritz Goldschmidt.

The Allende Meteorite fall, the most important stoney meteorite shower on record, was first seen in the early morning of February 8, 1969 as a fireball descending towards the southern Chihuahuan village of Pueblito de Allende, Mexico, approximately 340 miles south of El Paso, Texas. Exploding into pieces during its journey through the atmosphere, the meteorite fell over one of the largest strewn fields (the meteorite's dispersal area) ever recorded, extending over 200 square miles (300 km). Within five days of the fall, Smithsonian scientists Brian H. Mason and Roy S. Clarke, Jr., had arrived in Mexico and were collecting specimens with the help of local schoolchildren who agreed to look for meteorites on the condition that they would be provided with soft drinks. This motley crew was able to collect over a ton of material, with specimens ranging from as small as one gram to 242 pounds (110kg). The scientists were also aided by ASARCO (American Smelting and Refining Company) Mexicana, Parral, a mining company located close by.

The collected specimens were studied in various institutions, including with the new state-of-the-art equipment that NASA had acquired to study the lunar materials it was waiting to receive from the Apollo 11 mission. At the Smithsonian, scientists from both the National Museum of Natural History and the Smithsonian Astrophysical Observatory became involved in the analysis. During this examination, it was discovered that the Allende meteorite contained calcium-aluminum inclusions which represent some of the first solid matter to form in the solar system. Consequently the meteorite, a rare Type III carbonaceous chondrite, has been invaluable to scientists studying the formation of the early solar system.

The Allende meteorite has been important in the development of scientific fields, with its study resulting in meteoritics becoming an integral part of earth science as well as resulting in the birth of the new science of cosmo-chemistry, the intersection of geology, planetary science, astronomy, and astrophysics.

Inclusions in the Allende Meteorite / Brian Mason and S.R. Taylor

Author:

Mason, Brian Harold 1917-

Taylor, Stuart Ross 1925-

Smithsonian Institution

Physical description:

iii, 30 p. : ill. ; 26 cm

Type:

Electronic resources

Date:

1982

Summary:

Six discrete groups of inclusions have been distinguished in the Allende meteorite. Groups I, V, and VI are mostly melilite-rich chondrules, although some have been extensively altered to fine-grained aggregates; Groups II and III are mostly fine-grained aggregates made up largely of spinel and fassaite; Group IV are olivine-rich aggregates and chondrules. Each group has a distinctive trace-element pattern, most clearly shown by the rare-earth (RE) distribution pattern. Group I has an unfractionated pattern (except for a small positive Eu anomaly) at about 10-15 times chondrites; Group II has a highly fractionated pattern with depletion of the heavier lanthanides (Gd-Er) and negative Eu and positive Tm and Yb anomalies; Group III has an unfractionated pattern at about 20 times chondrites, except for negative Eu and Yb anomalies; Group IV has a relatively unfractionated pattern at 2-4 times chondrites; Group V has an unfractionated pattern at 10-20 times chondrites; Group VI has an unfractionated pattern at 10-20 times chondrites, except for positive Eu and Yb anomalies (i.e., complementary to Group III). The complex patterns of trace element distribution in these Allende inclusions indicate a complex history of formation of this meteorite from the solar nebula.